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2: The Basics of Provable Security

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    Edgar Allan Poe was not only an author, but also a cryptography enthusiast. He once wrote, in a discussion on the state of the art in cryptography: \({ }^{1}\)

    "Human ingenuity cannot concoct a cipher which human ingenuity cannot resolve."

    This was an accurate assessment of the cryptography that existed in 1841 . Whenever someone would come up with an encryption method, someone else would inevitably find a way to break it, and the cat-and-mouse game would repeat again and again.

    Modern 21st-century cryptography, however, is different. This book will introduce you to many schemes whose security we can prove in a very specific sense. The codemakers can win against the code-breakers.

    It’s only possible to prove things about security by having formal definitions of what it means to be "secure." This chapter is about the fundamental skills that revolve around security definitions: how to write them, how to understand & interpret them, how to prove security using the hybrid technique, and how to demonstrate insecurity using attacks against the security definition.

    \({ }^{1}\) Edgar Allan Poe, "A Few Words on Secret Writing," Graham’s Magazine, July 1841, v19.

    This page titled 2: The Basics of Provable Security is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Mike Rosulek (Open Oregon State) via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.

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